| 摘要 |
PURPOSE:To prevent deterioration of a picture quality, caused by fluctuation of a focus position, by correcting the focus position in accordance with a temperature. CONSTITUTION:A light beam exposure device exposes a sensitized material 54 by a recording lens 50. The recording lens 50 is arranged movably in a direction of an optical axis while converging a light beam. A temperature in an internal part of the before-mentioned device is measured by a temperature sensor 70. In a control circuit 78, a table for representing a focus position relating to the above-mentioned temperature is stored to move the recording lens 50 in the optical axis direction by controlling an actuator 80 so that a focus of the recording lens 50 is positioned in the focus position in accordance with the temperature, measured by the temperature sensor 70, by referring to the above-mentioned table. Consequently, the focus position of the recording lens 50 is maintained to the adequate position regardless of the temperature. |
